I've restarted photoshop and my computer, but I'm still running into this problem. When I try to use the adjustment brush, even when all settings are on zero, it dramatically darkens the area that I want to work with. Does anyone have any idea how to "reset" the settings for the adjustment brush in camera raw? I have version 9.1.1, and I have not installed any updates recently. The darkening is still there but less when I turn the flow down to one. This problem came up about a week ago when I was processing some photos and hasn't gone away since.

Use Photoshop menu Edit>Preferences>Camera RAW. If the Performance checkbox Use GPU is check uncheck it. Then try the filter again. Witht CC 2017 I have had problems using ACR adjustment brush even have seem crashes. ACR has also unchecked it on its own. Other version of PS with ACR Preference use GPU checked seem to work OK.

There is no preferences under edit for me. If I go to photoshop-> preferences->camera raw it pulls up a menu, but attached is what it looks like. There is no GPU or ACR box to check. I'm running photoshop CS6 version 13.0.6.

I would uninstall your current Camera Raw Plugin then restart your Mac.

You can delete it from : Library (computer library) > Application Support > Adobe > Plug-ins > CS6 > File Formats > Camera Raw.pluginThen reinstall it - you can download a new version of the same release (9.1.1) from Camera Raw installer for Adobe Photoshop CC and CS6